That's right, though you may/will run into the problem of very small values in which case you can use this fix:
cd bold/analysis x = load('X'); tirf = x.flac0.ev(3).tirf; Xirf = x.flac0.ev(3).Xirf; scalef = sum(Xirf .* repmat(tirf,[1 size(Xirf,2)]));
scalef will be something like 184. Multiply the percent signal change you get by this number. BTW, this problem is fixed in version 5.
doug
Adam Nitenson wrote:
Hi Freesurfers,
I am trying to analyze functional activity in individual subjects.The structural constraint is a dACC label and the functional constraint is positive activation at a specific timepoint (6 sec after stimulus). I was just wondering what the numbers following the "# of estimates per condition" row actually represented, and how I could convert these to % signal change. I saw in an archived email http://www.mail-archive.com/freesurfer@nmr.mgh.harvard.edu/msg00171.html that someone mentioned taking those values, dividing by the baseline offset value (row 4) and multiplying by 100 to get % signal change. Is this a valid method?
Adam Nitenson, B.S. Brain Genomics Lab Massachusetts General Hospital
PS Here are the commands I used if that helps:
func2roi-sess -roidef lh_dACC -analysis RM_correct_error -anatlabel lh.dACC -maskcontrast error_vs_correct -maskthresh 0.000000001 -masktail pos -maskframe 5 -maskmap sig -sf /autofs/space/ventzl_036/users/RespMon12C/subject_lists/caitlin_SZerrorcorrect.txt -d /autofs/space/ventzl_036/users/RespMon12C/subjects
roisummary-sess -roidef lh_dACC -analysis RM_correct_error -sf /autofs/space/ventzl_036/users/RespMon12C/subject_lists/caitlin_SZerrorcorrect.txt -d /autofs/space/ventzl_036/users/RespMon12C/subjects -sumfile /autofs/space/ventzl_036/users/RespMon12C/ROI_Analysis/lh_dACC _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer